Objective: To observe the three states of water (solid, liquid, and gas) and identify the conditions that cause water to change states.
Materials:
* Ice cubes
* Water
* Bowl
* Saucepan
* Thermometer
Procedure:
1. Place a few ice cubes in a bowl.
2. Observe the ice cubes. What do they look like? What is their temperature?
3. Let the ice cubes sit at room temperature for a few minutes. Observe what happens.
4. Place a saucepan filled with water on the stove. Turn the heat on to medium.
5. Observe the water as it heats up. What happens?
6. Continue to heat the water until it boils. Observe what happens.
7. Turn off the heat and let the water cool down. Observe what happens.
Observations:
* At room temperature, ice cubes are solid. They are cold and hard.
* When ice cubes are left at room temperature, they melt and turn into liquid water.
* When liquid water is heated, it turns into water vapor. Water vapor is a gas.
* When water vapor is cooled, it condenses and turns back into liquid water.
Conclusion:
Water can exist in three states: solid, liquid, and gas. The state of water depends on its temperature. When water is cold, it is solid. When water is heated, it turns into liquid. When water is heated even more, it turns into gas.
Experiment 2: Water's Boiling Point
Objective: To determine the boiling point of water at different altitudes.
Materials:
* Saucepan
* Water
* Thermometer
* Stopwatch
Procedure:
1. Fill a saucepan with water.
2. Place the saucepan on the stove. Turn the heat on to medium.
3. Place the thermometer in the water.
4. Observe the temperature of the water as it heats up.
5. When the water starts to boil, note the temperature on the thermometer.
6. Repeat steps 1-5 at different altitudes.
Observations:
* The boiling point of water is 100 degrees Celsius at sea level.
* The boiling point of water decreases as the altitude increases.
Conclusion:
The boiling point of water depends on the air pressure. At sea level, the air pressure is higher, so the boiling point of water is higher. At higher altitudes, the air pressure is lower, so the boiling point of water is lower.
